1. Field of the Invention
The present invention relates to power supply systems and more particularly, to a high-power induction-type power supply system and its data transmission method, which allows transmission of power supply and data signal at the same time with less power loss. By means of the supplying-end coil of the supplying-end module and the receiving-end coil of the receiving-end module, the system induces transmission of power supply and transmission of data signal, lowering power loss during transmission and enhancing wireless charging and data transmission performance.
2. Description of the Related Art
Following fast development of electronic and internet technology, many digitalized electronic products, such as digital camera, cellular telephone, multimedia player (MP3, MP4) and etc., have been continuously developed and have appeared on the market. These modern digital electronic products commonly have light, thin, short and small characteristics. However, for high mobility, power supply is an important factor. A mobile digital electronic product generally uses a rechargeable battery to provide the necessary working voltage. When power low, the rechargeable battery can be recharged. For charging the rechargeable battery of a digital electronic product, a battery charger shall be used. However, it is not economic to purchase a respective battery charger when buying a new mobile electronic product. Further, when one spends a big amount of money to purchase different mobile electronic products, a special storage space is necessary for the storage of the mobile electronic products. Further, it is inconvenient to carry and store many different mobile electronic products and the related battery chargers.
Further, when using a battery charger to charge a mobile electronic apparatus, the user must connect the connection interface (plug) of the battery charger to an electric outlet and then connect the connector at the other end of the battery charger to the mobile electronic apparatus, enabling the mobile electronic apparatus to be charged. After charging, the mobile electronic apparatus is disconnected from the battery charger. As conventional battery chargers must be used where an electric outlet is available, the application of conventional battery chargers is limited. When in an outdoor space, conventional battery chargers cannot be used for charging mobile electronic apparatuses.
Further, except battery charging, a mobile electronic apparatus may need to make setting of related functions, data editing or data transmission. A user may directly operate the mobile electronic apparatus to make function setting or to input data. However, some mobile electronic apparatus (such as MP3 player, MP4 player, digital camera, electronic watch, mobile game machine, wireless game grip, wireless controller) do not allow direct setting or data transmission. When making function setting or data transmission, an external electronic device (computer, PDA) must be used. Further, when charging a mobile electronic apparatus, it may be not operable to transmit data. Further, wireless induction power supply systems (or the so-called wireless chargers) are commercially available. These wireless induction power supply systems commonly use two coils, one for emitting power supply and the other for receiving power supply. However, the energy of wireless power supply is dangerous and will heat metal objects. They work like an electromagnetic stove. The use of a wireless induction power supply system has the risk of overheat damage of the charged device.
The prior art discloses a wireless charger data transmission method, which adopts asynchronous serial format that is a computer UART (universal asynchronous receiver/transmitter) format. This format is not specifically designed for induction type power supply system. In actual wireless charging operation, it has drawbacks as follows:
1. During signal modulation, resistive load is added to the receiving-end to reflect signal to the supplying-end coil. During signal generation period, the power of the receiving-end in receiving power supply from the supplying-end is interrupted. Further, when increasing the power during transmission of power supply, the power supply quality will be affected, causing charging instability.
2. When transmitting a data signal, data signal analysis is determined subject detection of current variation at the supplying-end coil. When the receiving-end is outputting power supply and the load has been changed, variation of the electric current at the supplying-end coil will occur. At this time, data code analysis will be affected due to output to the load, resulting in an incorrect data signal.
3. The power converting circuit and data transmission circuit at the receiving-end are of the same loop. When system power is enhanced, data transmission becomes unstable.
4. In order to sense the presence of the receiving-end during the standby mode, it is necessary to transmit a sensing signal that is much longer than one complete transmission data code. The longer the length of the sensing signal is the higher the consumption of power supply will be. Further, transmission of a sensing signal will heat the surrounding metal.
Therefore, it is desirable to a high-power induction-type power supply system that eliminates the problem of power loss of the prior art designs during charging, function setting or data transmission, and the problem of data signal interference during synchronous charging operation and data transmission.